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Biomedical subjects

J Mira

Publications and source records attributed to J Mira.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prevalence and surgical complications of pseudoexfoliation syndrome in Portuguese patients with senile cataract.

PURPOSE: To determine the prevalence and surgical complications of pseudoexfoliation syndrome (PES) in a Portuguese population of patients with senile cataract. SETTING: Department of Ophthalmology, Coimbra University Hospitals, Coimbra, Portugal. METHODS: In a prospective study, 183 consecutive patients with senile cataract referred to the Implant and Refractive Surgery Section of the Department of Ophthalmology were examined for PES. To determine the occurrence of intraoperative and postoperative complication of extracapsular extraction with posterior chamber intraocular lens implantation in patients with PES, two groups of similar age were compared: one with PES (n = 31) and a control group without PES (n = 31). RESULTS: The prevalence of PES in the 183 Portuguese patients with senile cataract was 23.5%. There was statistically significant difference between the two groups in the presence of phacodonesis (P < .05), insufficient intraoperative mydriasis (P < .001), need to perform sphincterotomies to facilitate nucleus expression (P < .01), and formation of pupillary fibrin membranes in the postoperative period (P < .01). These complication were more frequent in the PES group. Zonular breaks also occurred more often in patients with PES, although this was not statistically significant. CONCLUSIONS: Pseudoexfoliation syndrome was a common condition in patients with senile cataract having surgery in Portugal. Inadequate mydriasis was the major intraoperative difficulty; a pupil enlargement procedure should be performed in these cases. In the first days postoperatively, therapy with topical, subconjunctival, and systemic corticosteroids is recommended to reduce the inflammatory reaction in the anterior chamber.

Aged↗
PubMed1996

[Urinary tract infection caused by Haemophilus spp. in pediatrics: a rarely studied disease].

BACKGROUND: Haemophilus influenzae and Haemophilus parainfluenzae have been, in very seldom times, described as a cause of urinary tract infection (UTI), mainly on adults. Their real incidence has been scarcely studied. In view of this situation, we have investigated the cases occurred during the year of 1994 in our hospital, in Cádiz (Spain). METHODS: A total of 16,446 urine cultures from in-patients and ambulatory patients were processed, including the chocolate agar medium in the cultures. RESULTS: Urinary infection by Haemophilus supposed an incidence of 0.27% with respect to all positive urine cultures, and a 0.88% of the paediatric ones. H. influenzae was isolated in 7 occasions, and H. parainfluenzae in 3 of them. The 80% of the cases of UTI corresponded to paediatric patients. CONCLUSIONS: It would be convenient the inclusion of chocolate agar medium in the urine cultures for determined patients, chiefly on children.

Adult↗
PubMed1995

Spectrum of parvovirus B19 infection: analysis of an outbreak of 43 cases in Cadiz, Spain.

In the spring of 1993, an epidemic of infection with human parvovirus B19 occurred in Cadiz, Spain. Evaluation of the 43 patients in whom this diagnosis was confirmed revealed four groups of predominant manifestations: (1) hematologic manifestations in six cases (13.9%), including four of aplastic crisis and two of pancytopenia; (2) dermatologic manifestations in 23 cases (53.4%), including 10 of erythema infectiosum and one of erythema multiforme ampullosum; (3) arthralgias/arthritis in nine cases (20.9%), including two with a chronic course; and (4) infection during pregnancy in three cases (7.0%), including two that ended in abortion. Of the 43 patients, 37.2% presented with fever and adenopathies, and these were the only manifestations in two cases. The appearance of clinical disease correlated with modifications in isotype and serum level of specific antibodies to parvovirus B19; the disappearance of IgM antibodies coincided with the resolution of clinical manifestations. Although their presence did not correlate with the course of the disease, the detection of circulating immune complexes in 81.6% of cases supports the possibility that some manifestations were immune mediated.

Adolescent↗
PubMed1995

Expression of apolipoprotein J in the uterus is associated with tissue remodeling.

The endometrium is a dynamic tissue that, in response to hormonal cues, undergoes cycles of growth and involution. Extracellular factors required for this remodeling are poorly understood. The potential role in endometrial turnover of apolipoprotein J (apoJ), a secretory glycoprotein that can bind lipids and membrane-active proteins, is proposed on the basis of its spatial and temporal patterns of expression during normal cycling, after ovariectomy, and in response to hormone manipulation. In the mouse, apoJ mRNA was expressed in uterine luminal and glandular epithelial cells coincident with the presence of apoJ protein. The apoJ gene was differentially expressed in the glandular and uterine luminal epithelial cells during the estrous cycle and following hormone depletion. Expression of apoJ was not induced in ovariectomized mice by estrogen, progesterone, or dexamethasone treatment alone. Progesterone administration after an initial estrogen pretreatment, however, resulted in dramatic induction of apoJ as the progesterone level declined. In contrast, apoJ was not induced when a long-lived progesterone analog, medroxyprogesterone, was substituted for progesterone. In the human menstrual cycle, apoJ was present in glandular lumens only during the late secretory phase. Declining progesterone levels, causing substantial tissue reorganization, are characteristic of the times of marked apoJ induction in uterine epithelial cells. These expression patterns are consistent with apoJ functioning as an extracellular cytoprotectant by mediating clearance of and/or neutralizing cytolytic tissue debris.

Animals↗
PubMed1993

Design and integration of a graphic interface for an expert system in oncology.

We describe a graphic user interface for an expert system in oncology. The main objectives of our work has been to facilitate the adaptation of the system to different clinical environments and potentiate the factors which more directly determine the acceptance of the system by its users. We present the design principles derived from the features of the clinical domain chosen and from the objectives of the system. These principles are reflected on the design of the screen and of the interaction and in the style of integration of the interface with the other components of the system. Underlying the application we describe is a graphic user interface management system which provides facilities for the fast prototyping and integration of interfaces. We describe here those features of this tool which make the practical application of the design principles we consider possible.

Clinical Protocols↗
PubMed1993

A modular knowledge base for the follow-up of clinical protocols.

From the knowledge engineering point of view, the observation of patients subjected to clinical protocols of therapy constitutes a domain characterized by the existence of strongly structured knowledge. We have approached the problem from the perspective of a homogeneous and modular knowledge representation theory, based on the concept of Generalized Magnitude. This concept arises from identifying and collecting all possible facts of a domain established a priori, and being inspired by the concept of physical magnitudes. The Generalized Magnitudes scheme includes temporal extensions necessary to solve a medical problem for which exists a therapy and a follow-up plan with temporal specifications, and also facilitates the creation of advisory expert systems.

Drug Therapy, Computer-Assisted↗
PubMed1993

[Analysis of 40 cases of otomycosis].

AIM: Otomycosis is a rare clinical process, with peculiar characteristics concerning its etiology and presentation, depending on the geographic area. In order to determine the most common agents, the clinical and epidemiological aspects in mycotic external otitis, 40 episodes detected during one year period were analyzed. METHODS: Forty patients with otomycosis diagnosed (positive microbiological culture) were studied. Fungi were identified in accordance with morphological and biochemical criteria. RESULTS: Candida parapsilosis (42.9%) and Aspergillus niger (35.7%) were the commonest agents. In three episodes were found associated bacterial flora. The patients were males (60.0%), between the ages of 31-40 (35.0%) and over 50 years old (37.5%). The symptoms were the usual for these processes: serous fluid, otalgia and itching. The majority of the episodes occurred in the summer (57.5%) and autumn (30.0%), due to sea bathing (90.0%), trauma (27.5%) and prior antimicrobial treatment (40.0%). CONCLUSIONS: Candida parapsilosis is as an important pathogen of otomycosis in our environment, though the participation of Aspergillus niger is also remarkable, as it happens in other geographic areas. The contact with seawater and the antimicrobial treatment are the main factors which favor the infection; climatical conditions could cooperate to it in great extent. The observed symptoms are similar to the bacterial otitis, but of lesser intensity.

Adolescent↗
PubMed1992

Improved detection of HIV p24 antigen in serum after acid pretreatment.

HIV-1 p24 antigen was detected in 554 sera (509 from HIV-1 seropositive individuals and 45 sera from seronegative controls) using a conventional method with acid pretreatment of the sample in order to separate the p24 antigen/anti-p24 antibody immune complexes. In asymptomatic individuals there was a substantial increase in antigen detection (48.2% vs 8.4%). Similar results were also observed in ARC (59.1% vs 12.2%) and AIDS patients (85.7% vs 37.1%). It can be concluded that the acid treatment improves the sensitivity of conventional techniques to detect HIV-1 p24 antigen.

Female↗
PubMed1991

Fuzzy K-nearest neighbor classifiers for ventricular arrhythmia detection.

We report a study of the efficiency of 4 classifiers (the K-nearest-neighbor and single-nearest-prototype algorithms, each as parametrized by both Fuzzy C-Means and Fuzzy Covariance clustering) in the detection of ventricular arrhythmias in ECG traces characterized by 4 features derived from 7 spectral parameters. Principal components analysis was used in conjunction with a cardiologist's deterministic classification of 90 ECG traces to fix the number of trace classes to 5 (ventricular fibrillation/flutter, sinus rhythm, ventricular rhythms with aberrant complexes and 2 classes of artefact). Forty of the 90 traces were then defined as a test set; 5 different learning sets (numbering 25, 30, 35, 40 and 45 traces) were randomly selected from the remaining 50 traces; each learning set was used to parametrize both the classification algorithms using both fuzzy clustering algorithms and the parametrized classification algorithms were then applied to the test set. Optimal K for K-nearest-neighbor algorithms and optimal cluster volumes for Fuzzy Covariance algorithms were sought by trial and error to minimize classification differences with respect to the cardiologist's classification. Fuzzy Covariance clustering afforded significantly better perception of cluster structure than the Fuzzy C-Means algorithm, and the classifiers performed correspondingly with an overall empirical error ratio of just 0.10 for the K-nearest-neighbor algorithm parametrized by Fuzzy Covariance.

Algorithms↗
PubMed1990

Multimicroprocessor system for online monitoring in a CCU.

A real-time monitoring system for physiological signals, developed for patients in coronary care units (CCUs), is described. This system monitors the signals that have the greatest clinical value in a CCU environment (ECG and cardiovascular pressures), taking charge of detecting dangerous situations and of extracting information significant to the correct monitoring of the patient. The information it extracts, mainly from the ECG, is presented to the user in an ergonomic way using written reports and graphs which collect and compile the information, facilitating its interpretation. Some utilities have been developed to allow the user to modify certain monitoring conditions as well as to correct results derived from them, thereby improving the reliability of the monitoring process. The system uses a multimicroprocessor architecture (imposed by the need to perform a large number of tasks in real time) with a block based on the VME bus, charged with acquiring and processing the monitored signals, and an IBM-compatible PC/XT which is used as a system user interface and a massive storage device in which the information resulting from the monitoring of signals is stored.

Coronary Care Units↗
PubMed1990

Fuzzy beat labeling for intelligent arrhythmia monitoring.

The performance in automatic diagnosis of cardiac rhythm based on the analysis of the electrocardiographic signal (ECG) is strongly conditioned by the correct classification of each beat detected. In this work we present a fuzzy classifier of beats that applies empiric criteria and that permits it to ignore the frequent lack of clarity in the information coming from previous stages within ECG processing. The classification of each beat is performed applying diffuse conditional statements which represent the knowledge of the cardiologist expert and that use a set of descriptions of the temporal and morphological attributes of the analyzed beat. The process of classification is completed with information derived from the consideration of "families," which group beats that have QRSs of similar morphology, and with information brought in by the user himself in the monitoring process. The modularity of the classifier that has been developed facilitates the incorporation of new descriptions and classification criteria in order to increase its reliability. The design process proposed has a structure that is transferable to other analysis and event classification processes.

Arrhythmias, Cardiac↗
PubMed1989

Algorithmic sequential decision-making in the frequency domain for life threatening ventricular arrhythmias and imitative artefacts: a diagnostic system.

A preliminary study to approach the problem of reliably detecting life threatening ventricular arrhythmias in real time is described. An algorithm (DIAGNOSIS) has been developed in order to classify ECG signal records on the basis of the computation of four simple parameters calculated from a representation in the frequency domain. This algorithm uses a set of rules constituting an operative classification scheme based on the comparison of the parameters with a set of pre-established thresholds. This allows us to differentiate four general categories: ventricular fibrillation-flutter, ventricular rhythms, imitative artefacts and predominant sinus rhythm.

Algorithms↗